1. Field of the Invention
The present invention, in general, relates to aquatic structures and, more particularly, to floating, fixed-in-place docks that are used to moor boats.
There are known types, of structures that are similar but different than docks. They are called piers. These types of structures are fixed in position with a portion of the structure disposed over water and at an elevation that is greater than the highest anticipated water level. Because these structures are fixed in position relative to the earth, they do not float. Accordingly, they do not provide a surface that maintains itself a fixed distance above a surface of the water. This is essential for a dock to moor boats. Accordingly, piers are not generally suitable for use as a dock to moor boats (vessels).
Docks, in general, are well known types of structures that are used to moor boats that vary in size from kayaks to large yachts. They are disposed on the water and secured on the horizontal plane where they float. They are generally secured along both an X axis and a perpendicular Y axis relative to the earth. Because docks float they rise and fall along a vertical, or Z axis in accordance with changes in the water level. These changes are brought about by changes in the tide and by many other factors, such as the balance of inflow and outflow of water into lakes and rivers, as well as wave action and loading.
The X axis, for the description herein, is perpendicular to and extends away from the shoreline. The Y axis is parallel with respect to the shoreline. Both the X and the Y axis are on a horizontal plane. The Z axis is on a vertical plane.
As such docks provide an upper surface that remains a fixed distance above the surface of the water that they are disposed on. Therefore, boats are able to pull up alongside the dock and secure (i.e., tie) the boat to the dock. People are then able to embark (i.e., leave the dock and board the boat) or disembark (i.e., leave the boat and step back onto the dock). The dock therefore serves as an intermediate structure to allow access to and from the boat with respect to the shore.
For small applications, such as a private dock for one or a few boats, a single section of dock is often used. A typical dock section includes a width of several feet and a length from about fifteen to well over twenty feet long. Wider and longer dock sections are also known.
For larger applications, a plurality of dock sections are secured together in a preferred pattern. Sometimes, a plurality of dock sections are attached together in a linear arrangement. This allows for access to water that is further away from the shoreline and presumably deeper. Sometimes, a plurality of dock sections are attached together, usually by a hinge, and form a main section of dock. From the main section other shorter sections are secured at one end, usually by a hinge to the main section, and branch off in a perpendicular direction. Generally, docks systems are built to provide a maximum amount of dock perimeter (for boats to moor) while encompassing a minimum amount of surface area. Docks systems are also sized to accommodate the size of boats that are expected to be moored.
To consider how a dock is maintained in place, consider a simple single section type of dock that extends away from the shoreline in the X axis. The dock is fixed in place along both the X and Y axes at a first end that is proximate the shoreline and at a second end that is disposed away from the shoreline. There are numerous ways of accomplishing this.
A common way is to hingedly attach the first end to a structure that is anchored or otherwise secured to the ground (i.e., shoreline). Typically, a hinge is used at the first end to anchor the dock to the structure. The hinge allows the dock to pivot about a hinge axis in response to wave action.
The first end of the dock must also be able to move relative to the water in a vertical direction along the Z axis. Either the first end of the dock is able to rise and fall freely on the Z axis or it is secured to a type of structure that is able to rise and fall in response to changes in water level.
To secure the dock at the second end, most commonly either a vertical hole (that may be reinforced with a pipe lining) is provided through the dock or, alternately, a three-eighths inch galvanized plate with a horizontal ring attached thereto is secured to the dock. When the hole passes through the dock it is known as a “spud well”. When the ring is attached to the dock the ring is disposed off to the side of the dock and is known as a “pile guide”. The pile guide is attached where needed for a pile (i.e., a vertical pipe) to pass through.
The vertical pipe (or pile) is driven into the earth that is disposed under the water. The pipe (or pile) extends up above the highest anticipated water level and passes through the spud well or pile guide.
Accordingly, the dock is secured in position along both the X and Y axes and is able to rise and fall along the Z axis. If the structure that is disposed at the first end of the dock does not rise and fall along the Z axis, then the first end of the dock can include a pile to secure it in position and allow it to rise and fall.
Although more than one spud well can be used per dock section, it is common practice to secure the first end of the dock to the structure and use the pile (passing through the spud well or through the pile guide) to secure the second end of each dock section. A plurality of piles may be used to secure the main section in position, as desired.
Each branch section is typically hingedly attached to the main section and secured at a distal end by a pile. Most branch sections are perpendicular with respect to the main section, although there is no mandate that they be configured in that manner. Accordingly, any desired size of a dock system (assembly) can be provided. If desired, additional branch sections can also branch off from the branches to create even more elaborate dock systems.
The first end of the dock is attached to the structure in a variety of ways. One such method includes an intermediate ramp that is hingedly attached at a first ramp-end to the main structure and which is attached at an opposite end of the ramp to the first end of the dock, usually with wheels or rollers that accommodate changes in elevation of the dock. The main structure will typically include a walkway that is above the highest anticipated water line and which ultimately extends to terra firma. The first ramp-end provides access to the walkway. The first ramp-end and walkway are disposed above the highest anticipated water level.
Certain types of structures to which the dock may be attached are also adapted to rise and fall (i.e. float) in response to changes in the water level. One such type of floating structure is attached to a track. The track is attached to a sloping surface that extends from above the highest anticipated water level down into the water below the lowest anticipated water level.
As the water level rises, the structure is urged upward along the track. When the water level falls, the structure descends down the track. Accordingly the dock, which is hingedly attached to the structure, is able to move both upward and downward in response to changes in water level.
As the dock moves up or down, the dock exerts a force on the structure that causes it to correspondingly move up or down along the track. Therefore, it is the motion of the dock in the Z axis that supplies the force necessary to position the structure along the track.
With this type of arrangement, the dock is retained in position along the Y axis by the hinge. However, as the dock rises and falls it also moves in and out along the X axis as the structure moves up and down and follows the slope of the track. Accordingly, this type of a dock cannot be secured by a spud. Its use is generally limited to applications requiring a shorter dock length and for lighter duty applications. This is because the hinge cannot withstand an excessive loading of the dock along the Y axis. Therefore, this type of structure is not used to secure the dock where strong currents and excessive side loading is anticipated.
There are several common types of docks. A high-end dock includes a concrete deck over foam floatation that is encased in concrete. These types of docks are very heavy and therefore require maximum draft. Accordingly, they are not well-suited for use in strong cross-currents or if the water is likely to freeze. They, being heavy, are difficult to transport and generally, must be made near the site where they will be used.
Accordingly, a great deal of custom design and assembly is required to make the necessary forms, add reinforcing to the concrete, pour the concrete, insert the foam floatation, protect the foam flotation from damage, and then move the dock into position. Also, they are not especially attractive to view. Concrete docks are durable. However, they are very expensive to manufacture, transport, and install.
The most common type of dock includes a fabricated wooden frame over styrene (foam) blocks or billets. These docks are commonly custom made for each application. A very large inventory of materials is required that includes the lumber and fasteners. Each board is cut to size and fastened.
This type of dock can be manufactured to the preferred size, in accordance with the lumber that is available. However, wood docks have many disadvantages.
First, while their appearance is at first minimally acceptable, they soon bleach and begin to discolor. Aesthetically, wood docks have a short life expectancy. General decay and deterioration of the dock soon begins.
The appearance of this (and other types of docks that use billets for floatation) type of dock is affected by the floatation. The wooden frame is suspended by the floatation above the waterline. A space between a bottom of the wooden frame and water exists. This space is unsightly and can allow viewing of unsightly billets under the dock. Because this type of dock is so common and because no other aesthetically pleasing solution has been found, people have become somewhat accustomed to the appearance of these unsightly billets. Ideally, the siding of a dock would extend below the waterline, thereby eliminating the space and the billets from view.
Because the wood frame is elevated above the water a space is provided under the dock for oxygen (air). If a fire starts on the wooden portion, air is drawn in from under the dock and it feeds the flames. Accordingly, wooden docks are susceptible to fire. If the siding of the dock extended down below the waterline, air could not be drawn in to feed a fire on the surface of the dock. This would retard its spread.
The elevated design of wooden docks also permits the wind to pass under the dock. In extreme conditions with especially high winds these types of docks can be lifted by the wind and damaged.
Also, these types of docks experience a great deal of torsional (twisting) movement along their longitudinal length. This occurs from wave action as well as from loading. When a person steps on any dock when disembarking from a boat, the load is placed on an outside perimeter of the dock. This causes a torsional loading that twists the dock along its longitudinal length. Wave action also produces a torsional loading and unloading cycle.
While all docks experience torsional loading, wood docks lack stiffness and experience an excessive amount of twisting. This makes the dock feel less secure when a person steps near to its perimeter. This is because that portion of the dock descends a disproportionate amount while the remainder remains more afloat. The feeling this produces is of instability and a lack of certainty of footing. This is felt most commonly when stepping near the edge, such as when boarding or disembarking from a vessel. The resistance to movement is known as transverse stability. It is desirable that a dock experience minimum movement during use and therefore possess maximum transverse stability.
When a wave passed under a dock and is disposed near a longitudinal center thereof, the center of the dock is raised while the outside ends of the dock are unsupported. This causes the dock to flex downward at the ends. This is known as “hog” in the marine arts.
When two waves support the outside ends of a dock, the center of dock is unsupported and it sags. This is known as “sag” in the marine arts. The resistance to sag is dependant upon the stiffness of the dock. It is desirable that a dock have minimum sag, (i.e., maximum stiffness).
Ideally, a dock should be as stiff as possible, with minimum hog, sag, and twisting occurring.
In summary, hog, sag, and torsional loading subject all docks to loading and unloading cycles that stress the dock in all axes. Wood types of docks are especially prone to rapid deterioration. Accordingly, wood docks begin to lose stiffness quickly because the fasteners that secure the members together concentrate the loading and unloading forces and deform the wood. As the components expand, contract, or twist these movements are arrested by the fasteners that secure them together.
In other words, the repeated cycles of transverse (torsional) and longitudinal loading as well as expansion and contraction focus all of the forces on the fasteners. This causes the holes in which the fasteners engage to continually enlarge. The dock begins to experience increasing movement which, in turn, further exacerbates the process. This soon leads to the inevitable deterioration and general wearing away of the prior art type of wooden dock.
Wooden docks are also quite heavy and are not suited to transport. Therefore, they are generally assembled in-situ. Additionally, when a change in dock design or dimension is required, a completely new set of plans are required and a new list of materials (LM) is required. Additionally, it takes a very long time to cut each member and fasten them together. The time of assembly and therefore the cost is high.
An appendix, attached hereto, provides a comparison of the list of materials between a comparable wood dock and the instant monolithic dock. This provides a ready visual indication as to the complexity of manufacture, the increased inventory of materials, and the custom design nature of wood docks as compared to the instant invention.
Also, some docks are used in bodies of water that can freeze. The expansion of the ice is especially destructive to virtually all existing types of docks. This is because most existing types of docks are relatively heavy for their size. Accordingly, a great deal of draft (i.e., depth of the dock in the water) is required. This places a significant amount of the dock in the water exactly at the level where the water is prone to freeze and therefore damage the dock.
When a prior art type of dock that requires substantial draft (i.e., several inches to well over a foot) is in water that freezes, it is virtually impossible for the dock to be urged up out of the water and on top of the ice as it freezes. Accordingly, the ice exerts great pressure on the side walls of the dock, crushing the dock.
Also, prior art types of dock generally have vertical sidewalls. When the water freezes with such a type of dock there is no vertical or uplifting force that is exerted on the dock. It is desirable for a dock that is disposed in the water to be urged up and out of the water as the water freezes. Because of the draft required and the vertical sidewalls of existing prior art docks, this has not heretobefore been possible to accomplish.
There are numerous other problems that have plagued prior art types of docks, either increasing cost and time of manufacture or decreasing reliability and life expectancy.
For example, it has been difficult to create sufficiently strong spud wells with prior art types of docks. Similarly, it has been difficult to include the ducting (i.e., conduit) for utility routing with prior art types of docks. It has also been difficult to provide access areas to the utilities, known as “sunken vaults” with prior art types of docks.
Also, the greater mass and size, and therefore the higher center of gravity of prior art types of docks makes them more prone to tipping or worse yet, tipping over if sufficient side (transverse) loading is applied. It is desirable to make a dock as light as possible and with as low a center of gravity as possible.
The most common prior art types of docks use spaced apart billets to float the dock. This detracts from stability. Accordingly, the floatation element (i.e., the billets) are disposed deeper in the water where they are at greater risk for damage from freezing.
Also, the billets are disposed inward from the edges and generally toward the longitudinal center of prior art types of docks. This provides less floatation near to the edges of the dock which, in turn, detracts from transverse (i.e., roll) stability.
Accordingly, these types of docks are less safe and feel less comfortable to walk on. Standing on an edge of five foot wide, free floating wood dock with foam floatation might cause the edge to sink an additional six to seven inches in the water. By comparison, a comparably sized monolithic dock with similar loading would only sink from about two to three inches at the edge.
For the purpose of comparison, a wooden sixteen foot long by six foot wide dock might weigh about 1600 pounds with a draft of five to six inches and have a total residual buoyancy (net load) of about 1600 pounds. A similar size concrete dock might weigh about 6000 pounds with a draft of about eighteen inches and have a residual buoyancy of about 2200 pounds. However, a comparable size monolithic dock would weigh approximately 900 pounds, draft around 1 inch, and have a residual buoyancy of about 5000 pounds. It is desirable for a dock to have a lower weight and a greater residual buoyancy.
It is also desirable to be able to provide the above-mentioned features and benefits in docks that are sized for specific applications. For example, a typical size monolithic dock designed for use with kayaks and other low to the water vessels would include a length of twenty feet and a width of five feet and a depth of about five and three-quarter inches. Even so, it would include a draft that is one inch or less and be able to support (i.e., float) approximately three-thousand pounds. This low of a draft and this high of a loading have previously been unavailable for such a comparably small-sized dock. Obviously, with a height that is less than six inches, the dock would have a very low center of gravity, also previously unavailable.
Accordingly, there exists today a need for a monolithic dock that helps to ameliorate the above-mentioned problems and difficulties as well as ameliorate those additional problems and difficulties as may be recited in the “OBJECTS AND SUMMARY OF THE INVENTION” or discussed elsewhere in the specification.
Clearly, such an apparatus would be a useful and desirable device.
2. Description of Prior Art
Docks are, in general, known. While the structural arrangements of the known prior art types of devices may, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.